权限没有,则隐藏 function forum_list_access_filter($forumlist, $gid, $allow = 'allowread') { global $grouplist; if (empty($forumlist)) return array(); if (1 == $gid) return $forumlist; $forumlist_filter = $forumlist; $group = $grouplist[$gid]; foreach ($forumlist_filter as $fid => $forum) { if (empty($forum['accesson']) && empty($group[$allow]) || !empty($forum['accesson']) && empty($forum['accesslist'][$gid][$allow])) { unset($forumlist_filter[$fid]); } unset($forumlist_filter[$fid]['accesslist']); } return $forumlist_filter; } function forum_filter_moduid($moduids) { $moduids = trim($moduids); if (empty($moduids)) return ''; $arr = explode(',', $moduids); $r = array(); foreach ($arr as $_uid) { $_uid = intval($_uid); $_user = user_read($_uid); if (empty($_user)) continue; if ($_user['gid'] > 4) continue; $r[] = $_uid; } return implode(',', $r); } function forum_safe_info($forum) { //unset($forum['moduids']); return $forum; } function forum_filter($forumlist) { foreach ($forumlist as &$val) { unset($val['brief'], $val['announcement'], $val['seo_title'], $val['seo_keywords'], $val['create_date_fmt'], $val['icon_url'], $val['modlist']); } return $forumlist; } function forum_format_url($forum) { global $conf; if (0 == $forum['category']) { // 列表URL $url = url('list-' . $forum['fid'], '', FALSE); } elseif (1 == $forum['category']) { // 频道 $url = url('category-' . $forum['fid'], '', FALSE); } elseif (2 == $forum['category']) { // 单页 $url = url('read-' . trim($forum['brief']), '', FALSE); } if ($conf['url_rewrite_on'] > 1 && $forum['well_alias']) { if (0 == $forum['category'] || 1 == $forum['category']) { $url = url($forum['well_alias'], '', FALSE); } elseif (2 == $forum['category']) { // 单页 $url = ($forum['threads'] && $forum['brief']) ? url($forum['well_alias'] . '-' . trim($forum['brief']), '', FALSE) : url($forum['well_alias'], '', FALSE); } } return $url; } function well_forum_alias() { $forumlist = forum_list_cache(); if (empty($forumlist)) return ''; $key = 'forum-alias'; static $cache = array(); if (isset($cache[$key])) return $cache[$key]; $cache[$key] = array(); foreach ($forumlist as $val) { if ($val['well_alias']) $cache[$key][$val['fid']] = $val['well_alias']; } return array_flip($cache[$key]); } function well_forum_alias_cache() { global $conf; $key = 'forum-alias-cache'; static $cache = array(); // 用静态变量只能在当前 request 生命周期缓存,跨进程需要再加一层缓存:redis/memcached/xcache/apc if (isset($cache[$key])) return $cache[$key]; if ('mysql' == $conf['cache']['type']) { $arr = well_forum_alias(); } else { $arr = cache_get($key); if (NULL === $arr) { $arr = well_forum_alias(); !empty($arr) AND cache_set($key, $arr); } } $cache[$key] = empty($arr) ? '' : $arr; return $cache[$key]; } ?>javascript - How to use the XOR "^" on two strings - Stack Overflow
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javascript - How to use the XOR "^" on two strings - Stack Overflow

programmeradmin7浏览0评论

I have two strings:

var temp1 = "6219000041889600";
var temp2 = "FFFFFFFFFFFFFFFF";

I would like to XOR these two, however I know that in JavaScript you cannot XOR string and can only for int.

So Is there a way to do this? I know for the first value i can use:

var temp1_A= parseInt(temp1); //equal to 6219000041889600

However

var temp1_B= parseInt(temp12,16) // yields 1152921504606847000 

Then performing temp1_A ^ temp1_B yields 1159140504648736600 (but this is decimal) and converting back to HEX is 10161825C85ADF58 which is not my desired result.

It should be (when both hex according to Here)

6219000041889600 ^ FFFFFFFFFFFFFFFF = 9DE6FFFFBE7769FF`

but how would I go about XOR'ing this value with 8-bytes of FF.

I have two strings:

var temp1 = "6219000041889600";
var temp2 = "FFFFFFFFFFFFFFFF";

I would like to XOR these two, however I know that in JavaScript you cannot XOR string and can only for int.

So Is there a way to do this? I know for the first value i can use:

var temp1_A= parseInt(temp1); //equal to 6219000041889600

However

var temp1_B= parseInt(temp12,16) // yields 1152921504606847000 

Then performing temp1_A ^ temp1_B yields 1159140504648736600 (but this is decimal) and converting back to HEX is 10161825C85ADF58 which is not my desired result.

It should be (when both hex according to Here)

6219000041889600 ^ FFFFFFFFFFFFFFFF = 9DE6FFFFBE7769FF`

but how would I go about XOR'ing this value with 8-bytes of FF.

Share Improve this question edited Jun 4, 2015 at 18:20 Evan Davis 36.6k7 gold badges52 silver badges58 bronze badges asked Jun 4, 2015 at 18:06 user2577497user2577497 4979 silver badges17 bronze badges 2
  • 1 JavaScript's binary operators currently only support up to 32-bit integers (4 bytes). To exceed that, you'll have to process the strings in segments that fit under that limit and concatenate the results. – Jonathan Lonowski Commented Jun 4, 2015 at 18:13
  • You'll need to either look for a BigInt implementation, or parse those hex strings to arrays of 32-bit ints and do the operation manually. – David Ehrmann Commented Jun 4, 2015 at 18:20
Add a ment  | 

1 Answer 1

Reset to default 8

You've left the bounds of the 31-bit integer precision in JavaScript. You'll need to process your strings in chunks:

function XOR_hex(a, b) {
    var res = "",
        l = Math.max(a.length, b.length);
    for (var i=0; i<l; i+=4)
        res = ("000"+(parseInt(a.slice(-i-4, -i||a.length), 16) ^ parseInt(b.slice(-i-4, -i||b.length), 16)).toString(16)).slice(-4) + res;
    return res;
}

or maybe easier char-by-char:

function XOR_hex(a, b) {
    var res = "",
        i = a.length,
        j = b.length;
    while (i-->0 && j-->0)
        res = (parseInt(a.charAt(i), 16) ^ parseInt(b.charAt(j), 16)).toString(16) + res;
    return res;
}
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